U.S. Pat. No. 3,995,563, which is owned by the assignee of this application, discloses an end closure which protects the rail car from illegal or unauthorized entry and which also protects the contents of the car from flying objects. The end closure comprises two sliding doors which can easily and quickly be moved between closed and open positions. When closed, the doors extend across the open end of the rail car. When open, the doors slide to a stored out-of-the-way position, permitting loading and unloading.
More specifically, each side wall of the rail car disclosed in that prior patent has a main portion which terminates a short distance from the end of the rail car, and also has an upright ladder panel beyond the end of the main side wall portion. The space between the main side wall portion and the upright ladder panel defines a vertical slot or gap through which one of the doors can move to open position. When the doors are open, the portions projecting through the slots are stored in open spaces on the outer sides of the side walls and do not materially limit or reduce the available loading space within the rail car. There is an upper ladder brace extending from the top of the main side wall portion to the top of the ladder panel, providing a cantilever support for the ladder panel. The upper ladder brace does not interfere with the movement of the door through the slot because it is positioned above the door.
Some time after the issuance of that patent, the assignee of this application designed and built and began marketing an end door construction with vertically extended doors. The door extensions reached above the level of the upper ladder braces. In order to avoid interference with the upper ladder braces, the door extensions were provided with cut-outs or notches to clear the upper ladder braces when the doors are moved to open position. This construction is also part of the prior art.
Also as part of the prior art is an end door construction with vertically extended doors in which there are no vertical slots in the rail car side walls. The side walls are bowed or bulged laterally outwardly of the door tracks so that the paths of the door are entirely inside the rail car. The side wall is not slotted, although there is a horizontal slot in the paneling connecting the top of each side wall with the roof of the rail car which clears the upper extended portion of the door when it is open.
In accordance with the general object of the present invention, involving the use of vertically extended doors, each door moves through a vertical slot in a side wall and is stored with a portion of the door outside the rail car. The ladder panel is cantilever supported by an upper ladder brace which is longer than the one used in the assignee's previous designs described above and is bowed laterally outwardly so as to be entirely outside the path of the door. Thus while the upper ladder brace still provides a connecting bridge between the main portion of the side wall and the ladder, it will not interfere with the movement of the door to open position.
Other objects and advantages of this invention will become apparent as the following description proceeds, especially when considered with reference to the accompanying drawings.